The Seattle Seahawkssigned their fifth-round pick to his four-year rookie deal, the team announced Thursday. NFL NEtwork's Mike Garafolo adds the deal is worth $2.8 million over four years and includes roughly $300,000 guaranteed.

In signing his first professional contract, the rookie linebacker officially joins his brother, cornerback Shaquill, on the Seahawks roster and takes another improbable step toward making a regular-season NFL roster. Shaquem Griffin lost his left hand at the age of four because of rare condition before birth, and his selection on the third day of the 2018 NFL Draft was one of the more inspirational moments in draft history.

"He looked very comfortable, very natural," Carroll told reporters. "He has a sense already for scheme and terminology. The position is the right spot for him, it looks like. We can be aggressive and use his speed."

Next up for Griffin on the path to the 53-man roster? The first round of Seattle's organized team activities (OTAs) begins Monday.